Oxygen Diffusion and Surface Exchange Coefficients of Porous La0.6Sr0.4Co0.2Fe0.8O3−δ Decorated with Co3O4 Nanoparticles

Autor:	J. Ascolani-Yael, A. Montenegro-Hernández, L. C. Baqué, L. M. Toscani, A. Caneiro, L. V. Mogni
Rok vydání:	2022
Předmět:	Renewable Energy Sustainability and the Environment Materials Chemistry Electrochemistry Condensed Matter Physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials
Zdroj:	Journal of The Electrochemical Society. 169:034514
ISSN:	1945-7111 0013-4651
DOI:	10.1149/1945-7111/ac49ce
Popis:	This work presents a comparative study of the diffusion D c h e m and surface exchange coefficients k c h e m of porous La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) and Co3O4 nanoparticles decorated LSCF electrodes. The study was carried out using the 3DT-EIS method, which combines Electrochemical Impedance Spectroscopy experiments with FIB-SEM tomography data through an adapted Transmission Line–Adler Lane Steele electrochemical model.A reduction of the polarization resistance of about 60% was measured for the Co3O4 decorated LSCF respect to the reference LSCF cathode, in air at 700 °C. The Co3O4 decoration was found to modify the ORR surface reaction limiting mechanism from O2 dissociation to O-ion incorporation, whereas the diffusion coefficient was not modified by the decoration, which represents a surface diffusion process for both electrodes. After the EIS measurements, the Co3O4 particles were almost no longer visible by Field-Emission SEM on the surface of the decorated sample, but signs that these particles play an active role in Sr Segregation were observed by STEM-EDS, in particular by concentrating the segregated SrO in the surroundings of the decorated particles.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::337497a939584367d99298698d661062 https://doi.org/10.1149/1945-7111/ac49ce Zobrazit plný text záznamu